某污水厂Bardenpho-MBBR准Ⅳ类水提标改造分析

Upgrading and Reconstruction to Meet Quasi Class Ⅳ Standard of Surface Water by Bardenpho-MBBR in a Wastewater Treatment Plant

浙江某污水处理厂设计规模为16 x 104 m3/d,采用Bardenpho - MBBR工艺进行升级改造,使出水水质由一级B标准提升至地表准N类水质标准。针对采用A/A/O工艺的生化池,保持总容积不变且不改变厌氧及缺氧段,通过对好氧段功能重新划分,增加后置缺氧区和后置好氧区,并在好氧区投加悬浮载体,将生化池改造为Bardenpho - MBBR工艺,强化脱氮除磷效果;MBBR区采用微动力混合池型,无需使用推流器,节约投资和运行成本,利于系统运行维护。改造后,生化段出水COD、NH;-N、TN均值分别为18. 80.0. 27,8.43 mg/L,在未投加碳源的情况下稳定达到了准IV类水质标准,生化段出水TP均值为0. 48 mg/L,大大减轻了后续深度处理工艺的除磷负荷;TN去除率较改造前提高了近1倍,这得益于前置缺氧区脱氮效率的提高、填料区的同步硝化反硝化(SND)作用及后置缺氧区的脱氮作用;对系统中微生物进行高通量测序,结果表明,填料对系统的硝化贡献率达到85%,并且填料上附着的反硝化菌占比达到6. 46%,证明好氧区悬浮载体上存在SND过程。Bardenpho - MBBR工艺能耗低、容积效率高、运行效果稳定,突破了常规工艺对TN去除的限制,适用于对出水TN要求严格的准IV类等高标准水质要求的污水处理厂新建及改造工程。

A wastewater treatment plant ( WWTP), designed treatment capacity of 16 x 104 m3/d in Zhejiang Province, was upgraded the effluent quality from the first class B criteria specified in GB 18918 - 2002 to quasi class IV standard of surface water through Bardenpho-MBBR process. By repartitioning the function of aerobic area, increasing post-anoxic & post-aerobic area and adding suspended carriers to aerobic area in biochemical reaction zone, the original biochemical tanks were upgraded to Bardenpho-MBBR process without changing the anaerobic and anoxic area and the totalvolume to enhance nitrogen and phosphorus removal effect. The micro-power mixing pool was adopted by the MBBR area, and there was no need to use pushers, which saved the investment and operation cost and was conducive to the system operation and maintenance. After retrofitting, the average effluent COD, NH;- N and TN of biochemical area were 18. 80 mg/L, 0. 27 mg/L and & 43 mg/L respectively, which steadily met quasi class IV standard of surface water without adding carbon source. The effluent TP was 0. 48 mg/L after biochemical reaction, which extremely reduced the advanced wastewater treatment load. The TN removal rate was nearly double that before the modification, which was attributed to the improvement of denitrification efficiency in the pre-anoxic area, simultaneous nitrification and denitrification ( SND) effect in MBBR, and the denitrification ability in the post-anoxic area. Highthroughput sequencing of microorganisms in the system showed that the contribution rate of suspended carriers to nitrification of the system reached 85%. In addition, the proportion of denitrifying bacteria attached to the fillers accounted for 6. 46%, which proved that SND took place on the suspended carriers in the aerobic zone. The Bardenpho-MBBR process has low energy consumption, high volumetric efficiency, stable operating results and breaks the limitations of conventional processes on TN removal, which is applicable to new construction and reconstruction of WWTP with strict requirements on effluent TN to meet quasi class IV standard of surface water.